Liquid crystalline polyester composition, method of producing the same and molded product manufactured from the same

Abstract

A liquid crystalline polyester composition contains at least 100 parts by weight of liquid crystalline polyester having different structural units and 10 to 100 parts by weight of glass fiber, wherein the glass fiber has a weight-average fiber length (Mw) of 200 to 500 μm, and content of specific glass fiber having fiber length of not less than 1500 μm is 0.1 to 5.0 percent by weight to a total amount of the glass fiber.

The invention claimed is: 
     
       1. A liquid crystalline polyester composition, at least containing 100 parts by weight of liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and 10 to 100 parts by weight of glass fiber, wherein
 the glass fiber has a weight-average fiber length (Mw) of 200 to 500 μm and includes specific glass fiber having fiber length of not less than 1500 μm, and 
 content of the specific glass fiber is 0.1 to 5.0 percent by weight to a total amount of the glass fiber 
 
       
         
           
           
               
               
           
         
       
     
     
       2. The liquid crystalline polyester composition according to  claim 1 , wherein
 the glass fiber has a ratio (D90/D10) of 90%-cumulative-frequency fiber length (D90) to 10%-cumulative-frequency fiber length (D10) in the cumulative weight fiber length distribution curve of not greater than 5.0. 
 
     
     
       3. The liquid crystalline polyester composition according to  claim 1 , wherein the glass fiber contained in the liquid crystalline polyester composition has a mode (S) of fiber length in a fiber length frequency distribution that is not less than 0.25 times but less than 0.90 times as much as the weight-average fiber length (Mw). 
     
     
       4. The liquid crystalline polyester composition according to  claim 1 , wherein
 content of the structural unit (I) is 65 to 80 mole percent relative to a total amount of the structural units (I), (II) and (III), 
 content of the structural unit (II) is 55 to 85 mole percent relative to a total amount of the structural units (II) and (III), and 
 content of the structural unit (IV) is 50 to 95 mole percent relative to a total amount of the structural units (IV) and (V). 
 
     
     
       5. A method of producing the liquid crystalline polyester composition according to  claim 1  comprising:
 melt-kneading at least liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and the glass fiber by an extruder having a plurality of supply ports; 
 supplying the liquid crystalline polyester from a first supply port located on an extruder drive system side; 
 supplying the glass fiber from a second supply port located downstream of the first supply port; and 
 controlling melt viscosity of the liquid crystalline polyester at a shear rate of 100 s −1  in a glass fiber supply section to 100 to 5000 Pa·s 
 
       
         
           
           
               
               
           
         
       
     
     
       6. A molded product manufactured by injection molding the liquid crystalline polyester composition according to  claim 1 . 
     
     
       7. A connector comprising the molded product according to  claim 6 . 
     
     
       8. The liquid crystalline polyester composition according to  claim 2 , wherein the glass fiber contained in the liquid crystalline polyester composition has a mode (S) of fiber length in a fiber length frequency distribution that is not less than 0.25 times but less than 0.90 times as much as the weight-average fiber length (Mw). 
     
     
       9. The liquid crystalline polyester composition according to  claim 2 , wherein
 content of the structural unit (I) is 65 to 80 mole percent relative to a total amount of the structural units (I), (II) and (III), 
 content of the structural unit (II) is 55 to 85 mole percent relative to a total amount of the structural units (II) and (III), and 
 content of the structural unit (IV) is 50 to 95 mole percent relative to a total amount of the structural units (IV) and (V). 
 
     
     
       10. A method of producing the liquid crystalline polyester composition according to  claim 2  comprising:
 melt-kneading at least liquid crystalline polyester having structural units (I), (II), (III), (IV) and (V) shown below and glass fiber by an extruder having a plurality of supply ports; 
 supplying the liquid crystalline polyester from a first supply port located on an extruder drive system side; 
 supplying the glass fiber from a second supply port located downstream of the first supply port; and 
 controlling melt viscosity of the liquid crystalline polyester at a shear rate of 100 s −1  in a glass fiber supply section to 100 to 5000 Pa·s 
 
       
         
           
           
               
               
           
         
       
     
     
       11. A molded product manufactured by injection molding the liquid crystalline polyester composition according to  claim 2 . 
     
     
       12. A connector comprising the molded product according to  claim 11 .